80) {    header('HTTP/1.1 503 Too busy, try again later');    die('Server too busy. Please try again later.');}*/// 建议最大负载不要超过3*N核，例如有16核（含8核超线程）则 16*3=48function get_server_load() {    if (stristr(PHP_OS, 'win')) {            $wmi = new COM("Winmgmts://");        $server = $wmi->execquery("SELECT LoadPercentage FROM Win32_Processor");                $cpu_num = 0;        $load_total = 0;                foreach($server as $cpu){            $cpu_num++;            $load_total += $cpu->loadpercentage;        }                $load = round($load_total/$cpu_num);            } else {            $sys_load = sys_getloadavg();        $load = $sys_load[0];        }        return (int) $load;}